Softened water

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U.P.Boiler

Member
Nov 15, 2015
29
Michigan , UP, Moran
I'm getting conflicting info. Is it ok to run softened water in a wood boiler? I treat the water with an anti-corrisive and the water is run through a filter as well.

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I'm a believer in no. The problems with soft water IMO is not worth it. Was finding too much staining from copper pipes in the domestic water system. So much in fact the system has been in bypass for 2 years now.
 
I loaded my 1,100 gallon pressurized system with softened water thinking it is good. Since then I have seen posted by a true professional hydronics person that it is not the best idea. I have not changed the water out and have not seen evidence of any problems, my fingers are crossed and only time will tell. If I were to load it today, I would research further before doing so.
 
When you soften water with a typical ion exchange softer you are adding salt in the exchange. Two sodium ions knock off the hardness from the resin. In doing so you increase the conductivity of the water, the added sodium ions.

Increasing conductivity can increase corrosion especially if you have dissimilar metals. the water becomes an electrolyte just like inside you truck battery. That is why softening often presents the blue green stains in your sink, tub, faucet areators. etc.

Sometimes with extremely hard water, over 20 GPG for example it becomes which is the lesser of two evils. The hard scaling water destroying HX surfaces, or the softened water adding conductivity? Tough call.

Ideally the water is deionized, RO or distilled as these methods remove all the minerals both the positive and negative ions cations and anions.
With pure water like this you may need to boost ph a bit as deionizing will drop ph.

I think it is always good to add some conditioner to systems, especially the multi metal systems.

Here is some examples and comparisons, from Idronics.
 

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Bob, No doubt that you have forgotten more about boilers than I can hope to ever know but in my other life I was involved in electroless nickel and nickel cobalt plating. Whet we found was that RO water was very corrosive because all the minerals and metals that were removed. The RO water wanted those minerals back so it attacked the interior of the reactors and the plating salts.
 
correct when you make water near 100% pure you drop the ph into the 6's. In a closed loop system that aggressive water will grab some metals from the piping, etc and balance to a mid 7 ph within a week, from the studies we have done, and testing in Europe..

the other option is to add a small amount of hydronic conditioner, my prefered method, with the DI or RO water. The conditioner will buffer the ph, add some O2 scavenges and some film provider. I feel it is an important final step for any system.

So clean with some hydronic detergent. Check the site water for hardness and TDS. Fix the water if needed, add the conditioners as needed.

It is possible to treat water that is out of spec with chemicals. These chemicals will keep solids in suspension to prevent scaling, not remove them. But you will need to add chemicals or boost them from time to time. A chemical romance if you will :)

If you have aluminum and stainless components I highly recommend good fill water and conditioners. Most boiler warranty depends on water quality meeting the spec in the manual. Here are a few US boiler standard, I doubt tap water in many places meets many of these limits.

In Germany the have a VDI Standard that inspectors use when the check boiler installations. Bad water, no inspection sign off!

Just today a group of us from the US and Canada agreed to put together a standard similar to the VDI 2035.
 

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I was told not to. My well water also had a higher sodium chloride level. I ended up hauling my water from the city filling station. 250 gal tote in a 3/4 ton pickup . I had to make 6 trips. The water cost me 7$. Gas was a bit more. Used a transfer pump to fill boiler
I think that is what I will be doing in the spring.

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More and more suppliers are getting DI units that you can rent or borrow to fill at the site. You buy the resin bags or cartridge and they supply the unit. Some wholesalers sell the filtered DI water in 55 drums or the totes.

Check the water you have first, in a few cases I found city and well water that was satisfactory.

Got gutters on your roof? Start collecting rain water. Water becomes hard as it contacts and absorbs minerals from the ground.
 
What do you mean by "suppliers"? I noticed Caleffi had a portable water treatment unit in one of their press releases a year or 2 ago. I called them to inquire about renting the a unit but they never got back to me....I'm in SW Wisconsin with very hard water. I need to find a source of good fill water this summer when I hope to get my system up...
 
Buy an Reverse Osmosis system. It removes hardness and PH ends up at 7.0. You will need to buffer the water so you won't get PH swings and test the buffer (KH) regular and as it drops add more buffer to keep it at 7.0. I have it running into a 35 gallon drum with a float valve when full it shuts off. I have a pump and hose to take it where I need it.

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It is always a good idea to check ph with and accurate meter, and the meters should be checked and re calibrated occasionally. The good meters generally come with 3 sample packages of fluid to calibrate with.

Different opinions on RO ph, some suggest 5-6 is typical. remember a big swing with 1 number change on a logarithmic scale.

I would always add a hydronic conditioner to aggressive, hungry water RO, DI or distilled to protect the metals.
 
In the spring ,I help my brother in law ,with his maple syrup operation. During the boiling process , condensate/ distilled water is taken off the equipment by way of the pre-heater and steam away. We collect about 300 gals during a 1200 gal sap run .I had thoughts of using this to fill my system when I get to that point. I would have it checked before it is used . Would this be a good idea?
 
Condensate is not equal to commercial distilled water. All kinds of contamination is possible from the environment that the condensation takes place. Would you drink condensate from a dehumidifier or ac coil in your furnace?
 
Condensate is not equal to commercial distilled water. All kinds of contamination is possible from the environment that the condensation takes place. Would you drink condensate from a dehumidifier or ac coil in your furnace?
I will do some testing on it this spring to get an idea of its make up. I 'm about a year away from filling the system so I'll have my well in and know the chemical make up of both
 
Condensate is not equal to commercial distilled water. All kinds of contamination is possible from the environment that the condensation takes place. Would you drink condensate from a dehumidifier or ac coil in your furnace?

Yes but a maple syrup evaporator is not a dehumidifier or ac coil. I have & will continue to drink the condensate that comes off ours - then again I know how well the equipment is cleaned. I have no idea though about it being good or bad for a heating system though. I would first think it would be akin to distilled water.
 
An important distinction not often made is that 'sodium' from a (properly functioning) water softener does not equal 'salt' or 'sodium chloride'. It's the chloride ion you really have to worry about. Softened water is often a good thing for boilers. You're removing the calcium, magnesium and other 'hard water' minerals which can lead to scaling and reduced performance, replacing them with soluble sodium compounds which typically cause no issues.

Sodium in itself is not corrosive. In fact, many boiler water treatment chemicals are based on sodium... sodium borate / sodium nitrite corrosion inhibitors, sodium carbonate for increasing pH, sodium sulfate oxygen scavengers, various sodium phosphates for alkalinity, etc.

The big key, though is to ideally fill once and leave that water as long as possible. With any fill, there will be small amounts of 'reactants' in the water... corrosive chloride, calcium and magnesium making scale, dissolved oxygen, etc. But once those react, the remaining water is stable and non-corrosive. So if you run a long time on that water, no additional issues. But if you add make-up water every week, you're adding new reactants to form more corrosion, scale, etc.
 
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Here in Vermont, there are at least two companies, that are bottling and marketing it. A good friend of mine has a sugaring operation and with RO equipment is taking natural 2 to 4 percent natural sap and bringing it up to 40 percent. I don't know what's left on the water that made it through the membrane. His boiler is about the size of a small locomotive and the pipe that sends the condensate to the drain is flowing at about 3 to 4 gallons per minute. Tastes like bottled water.as opposed to my delicious water here at home from my mineral rich drilled well.

He uses the water to clean his equipment.
 
We use the condensate for cleaning , floor wash down etc. Our tank holds 300 gals , so at the beginning of each run we will dump the majority of it. The evaporator has a scale build up that we clean off with a mild acid wash , a few times throughout the season . So the condensate has to be greatly reduced in the amounts of minerals. I'll need about 1900 gals total , so 1 seasons run should give me all I need . The kids wanted us to make a hot tub with the water cooled to about 100F,we'll see about that.
 
I installed a water softener when I built my home in 1980 and have not had any problems. At that time I installed a Tarm MB55 Solo Boiler. I filled the boiler with the soft water. That was 38 years ago. The system is pressurized with an expansion tank. After 38 years of use, I have never had any leak, or corrosion. The system was only filled once 38 years ago. I have never drained or flushed out the system.

I heat my home using a two row water coil, installed above the heat pump air handler. Hot water circulates through it from the Tarm Boiler. I heat my domestic water with an Amtrol Boiler Mate. I have fixed water flows through the water coil for various outdoor temperatures and a flow rate through the Boiler Mate heat exchanger that will heat 40 Gallons of water in an hour. My draft regulator is set to control the boiler water temperature to 170 degrees. Since my initial installation with softened water, I have not had to increase any flow rates as would be expected if the heat exchanger tubes developed a scale or coating that would reduce the rate of heat transfer.

John M.
 
A lot depends on the metals in your system. Many of the new boilers contain various grades of stainless steel and various aluminum alloys. Most systems have steel, copper and brass or bronze also. If your system is steel and copper water quality is not as critical as newer boilers and indirects.

The newer high efficiency boilers with stainless, as well as stainless indirect tanks are very sensitive to chlorides. The manufacturers are really adding cautions in the installation manuals regarding water quality.

Most will now refuse warranty on boilers and tanks if your water does not meet their spec. TDS readings will give you an indication of the amount of ions, but not the type. if you get high TDS readings you may want to have that water analyzed.

Water can be soft even 2 GPG but still have high TDS. Softening water tends to raise the TDS as it is a 2-1 ion exchange, depending on the metals in your system that may or may not create problem.

I'd suggest it depends on how hard your water is to determine if softening is better than not. Areas of Texas have water below 5 GPG but TDS over 600. Really no reason to soften that water, but you could bring down the TDS with RO, DI or other methods.
 
A lot depends on the metals in your system. Many of the new boilers contain various grades of stainless steel and various aluminum alloys. Most systems have steel, copper and brass or bronze also. If your system is steel and copper water quality is not as critical as newer boilers and indirects

So what I get out of that is the manufacturers telling me "So we used inferior manufacturing techniques and materials in order to improve our bottom line and we're leaving it up to you to jump through hoops in order to keep the unit from failing before it's time".

Where am I going wrong with that thought?

It's like the pickup truck. "carry all you want in the bed but in order not to disfigure the steel or have the load fall through the bottom, you'd better install a bedliner.
 
actually those bedliners create more problems then the solve- primarly rusting out of the bed floor- although that does depend on your location somewhat as it is an atmosphere related problem. mutilple metal types in mechanical connection to each other plus water sets up galvanic actions add in the various other components of typical tap water just compounds things and pure H20 doesn't resolve anything either. it becomes a balancing act.
 
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